Turkey can ban Islamic headscarves in universities, the European Court of Human Rights has ruled.
The headscarf issue divides Turkish society
The court rejected an appeal by a Turkish woman who argued that the state ban violated her right to an education and discriminated against her.
Leyla Sahin had brought the case in 1998 after being excluded from class at Istanbul University.
But the judges ruled that the ban was justified to maintain order and avoid giving preference to any religion.
Although overwhelmingly Muslim, Turkey is a secular republic and the Islamic headscarf is banned in all universities and official buildings.
The BBC's Sarah Rainsford in Istanbul says the verdict will have a major impact as more than 1,000 other women from Turkey have filed similar applications.
According to the court's ruling, which is final, the headscarf ban is based on the Turkish constitution's principles of secularism and equality.
In a society where men and women are equal, it said, a ban on religious attire such as the headscarf was justified on university premises.
"The court did not lose sight of the fact that there were extremist political movements in Turkey which sought to impose on society as a whole their religious symbols and conception of a society founded on religious precepts," the court's ruling added.
Our correspondent says the ruling is a bitter disappointment for Ms Sahin and her lawyers.
Ms Sahin, who now lives in Vienna, had argued the ban violated her right to study and discriminated against her for her religious belief.
Her defence team believe the decision is political and that the court feared the enormous implications of ruling otherwise for a mainly Muslim country.
But they point out that the headscarf ban applies to all Turkish universities, state or private, so that students are faced with an impossible dilemma - to ignore their religious beliefs or go without higher education.